Herein we describe a case of pyopneumopericardium that resulted from formation of an acquired esophagopericardial fistula in a patient with silent, benign esophageal ulcer disease. Atypical features on initial examination suggested congestive heart failure or a pneumonic process (or both). The delayed development of pneumopericardium disclosed on a chest roentgenogram led to the clinical recognition of the esophagopericardial fistula. Subsequent emergent pericardiocentesis relieved cardiac tamponade and enabled us to diagnose pyopneumopericardium. A radiographic contrast study with use of meglumine diatrizoate revealed the site of the fistula in the midesophagus. The esophagopericardial fistula was surgically closed, and our patient had a good final result. Formation of an esophagopericardial fistula is a relatively uncommon finding; of the 60 previously reported cases, only 10 patients have survived. As illustrated in the current case, early diagnosis and treatment, including pericardial drainage and intense antibiotic therapy followed by a well-planned operative closure of the fistula, are paramount for the successful management of esophagopericardial fistulas.